This invention relates to a sandwiching machine for depositing a semi-frozen comestible, such as ice cream, between two cookies to make an ice cream sandwich and more particularly, to an improved stencil assembly for use in such sandwiching machine.
Sandwiching machines utilizing the principle of rotary stencil deposition are known in the prior art, for example, Fay U.S. Pat. No. 2,997,453, Fay U.S. Pat. No. 3,119,352, Talbot U.S. Pat. No. 3,340,824, Rose U.S. Pat. No. 4,162,882, and Rose U.S. Pat. No. 4,469,021. The Fay and Talbot patents and Rose U.S. Pat. No. 4,162,882 each disclose a stencil assembly which includes a stencil supported by a driving hub and an idler hub, all rotating on a hollow stationary shaft or tube that is clamped in bearings on the frame of the sandwiching machine. Cream to be deposited is fed from one side of the stencil assembly for deposit on adjacent rows of cookies. In the Rose U.S. Pat. No. 4,469,021, cream is fed from one or two sources to each side of the stencil assembly and is uniformly discharged from the stencil assembly.
While the prior art devices, particularly Rose U.S. Pat. No. 4,469,021, function satisfactorily using a pasty cream or the like filling for a sandwich at room temperature, it has shortcomings when the product to be deposited on the cookies is a semi-frozen comestible, such as ice cream. It is desired that ice cream in a semi-solid state (at about 22.degree. F.) flow from a mixer-freezer to the stencil assembly for making of ice cream sandwiches. Stopping the flow from the mixer-freezer might cause a frozen-solid condition to occur within the mixer-freezer that could prevent further operation. If the sandwiching machine were at room temperature at start up, ice cream contacting the relatively warm surfaces within the stencil assembly would melt and be unsuitable for sandwiching or packaging. This would cause undesirable waste.
An object of the present invention is to provide a sandwiching machine for ice cream which includes an improved stencil assembly for maintaining a steady flow of ice cream through the stencil assembly, both when the shut-off valve is opened and when it is closed.
Another object of the present invention is to provide a sandwiching machine with an improved stencil assembly which incorporates a supply means, a return means, and shut-off and by-pass valve means including a shut-off valve for selectively permitting discharge of ice cream from the supply means onto a cookie or cookies and for diverting ice cream from the supply means to the return means when the shut-off valve is closed. Other objects and advantages of the present invention will be made more apparent hereinafter.